RCNP Project on Polarized 3He Ion Sourcese—From Optical Pumping to Cryogenic Method.

A polarized 3He ion source has been developed at RCNP for intermediate and high energy spin physics. Though we started with an OPPIS (Optical Pumping Polarized Ion Source), it could not provide highly polarized 3He beam because of fundamental difficulties. Subsequently to this unhappy result, we examined novel types of the polarized 3He ion source, i.e., EPPIS (Electron Pumping Polarized Ion Source), and ECRPIS (ECR Polarized Ion Source) experimentally or theoretically, respectively. However, attainable 3He polarization degrees and beam intensities were still insufficient for practical use. A few years later, we proposed a new idea for the polarized 3He ion source, SEPIS (Spin Exchange Polarized Ion Source) which is based on enhanced spin-exchange cross sections at low incident energies for 3He++Rb, and its feasibility was experimentally examined. Recently, we started a project on polarized 3He gas generated by the brute force method with low temperature (∼4 mK) and strong magnetic field (∼17 T), and rapid melting of highly polarized solid 3He followed by gasification. When this project will be successful, highly polarized 3He gas will hopefully be used for a new type of the polarized 3He ion source. [ABSTRACT FROM AUTHOR]